Electrical circuitry often must be protected from disruptions caused by electromagnetic interference (EMI) and radio frequency interference (RFI) entering the system. In addition to protecting electronic equipment against EMI/RFI energy there is also a need to protect the equipment against power surges owing to electrostatic discharges (ESD) and electromagnetic pulses (EMP). The high voltage generated by ESD and EMP can damage voltage sensitive integrated circuits and the like.
Frequently today's electronic circuitry requires the use of high density, multiple contact electrical connectors. There are many applications in which it is desirable to provide a connector with a filtering capability; for example, to suppress EMI and RFI, and transient suppression means to suppress EMP and ESD interference or other undesired signals which may exist in circuits connected by the connectors. To retain the convenience and flexibility of the connector, however, it is desirable that the filtering capability be incorporated into the connectors in a manner that will permit full interchangeability between the filtered connectors and their unfiltered counterparts. In particular, any filtered connector should retain substantially the same dimensions as the unfiltered version and should have the same contact placement so that either can be connected to appropriate mating connectors.
One means to protect against undesirable interference is by the use of shielding. One such shielding means is disclosed in U.S. Pat. No. 4,330,166. This patent discloses the use of a conductive spring washer seated in the plug portion of the connector so as to make electrical contact with the receptacle portion of the connector when the plug and receptacle are mated. One washer thus provides shielding for a multitude of electrical circuits. For adequate protection, it is essential therefore that there be no break in the continuity of the shielding.
Means for protecting against power surges include the use of additional specialized circuitry within equipment, such as voltage variable resistors.
Protection against power surges can also be achieved by the use of connectors having transient suppression devices associated with selected terminals within the connector, such as the connectors disclosed in U.S. patent application Ser. No. 758,712, entitled "Transient Suppression Device" and U.S. patent application Ser. No. 758,711 entitled "Transient Suppression Assembly" commonly owned by this assignee.
It is an object of the present invention to provide an EMP/ESD protected as well as EMI/RFI filtered electrical connector.
It is a further object of this invention to provide EMP and EMI protection for high density, multi-contact electrical connectors.
It is also an object of this invention to provide a method for assembling a filtered connector that at least in part lends itself to automatic equipment such as robotics.
Further it is an object of this invention to provide EMP and EMI protection for electrical connectors such that the protected connectors retain substantially the same dimensions and contact placement as their unprotected mateable counterparts.
It is an additional object of this invention to provide an environmentally sealed connector.